Burial Treatments Research Articles

Effects of sediment burial disturbance on macro and microelement dynamics in decomposing litter of Phragmites australis in the coastal marsh of the Yellow River estuary, China.

From April 2008 to November 2009, a field decomposition experiment was conducted to investigate the effects of sediment burial on macro (C, N) and microelement (Pb, Cr, Cu, Zn, Ni, and Mn) variations in decomposing litter of Phragmites australis in the coastal marsh of the Yellow River estuary. Three one-off sediment burial treatments [no sediment burial (0 mm year(-1), S0), current sediment burial (100 mm year(-1), S10), and strong sediment burial (200 mm year(-1), S20)] were laid in different decomposition sites. Results showed that sediment burials showed significant influence on the decomposition rate of P. australis, in the order of S10 (0.001990 day(-1)) ≈ S20 (0.001710 day(-1)) > S0 (0.000768 day(-1)) (p < 0.05). The macro and microelement in decomposing litters of the three burial depths exhibited different temporal variations except for Cu, Zn, and Ni. No significant differences in C, N, Pb, Cr, Zn, and Mn concentrations were observed among the three burial treatments except for Cu and Ni (p > 0.05). With increasing burial depth, N, Cr, Cu, Ni, and Mn concentrations generally increased, while C, Pb, and Zn concentrations varied insignificantly. Sediment burial was favorable for C and N release from P. australis, and, with increasing burial depth, the C release from litter significantly increased, and the N in litter shifted from accumulation to release. With a few exceptions, Pb, Cr, Zn, and Mn stocks in P. australis in the three treatments evidenced the export of metals from litter to environment, and, with increasing burial depth, the export amounts increased greatly. Stocks of Cu and Ni in P. australis in the S10 and S20 treatments were generally positive, evidencing incorporation of the two metals in most sampling times. Except for Ni, the variations of C, N, Pb, Cr, Cu, Zn, and Mn stocks in P. australis in the S10 and S20 treatments were approximated, indicating that the strong burial episodes (S20) occurred in P. australis marsh in the future would have little influence on the stocks of these elements. With increasing burial depths, the P. australis was particularly efficient in binding Cu and Ni and releasing C, N, Pb, Cr, Zn, and Mn, implying that the potential eco-toxic risk of Pb, Cr, Zn, and Mn exposure might be very serious. This study emphasized the effects of different burials on nutrient and metal cycling and mass balance in the P. australis marsh of the Yellow River estuary.

Effects of sediment burial on grass carp,Ctenopharyngodon idella(Valenciennes, 1844), eggs

It is thought that grass carp (Ctenopharyngodon idella) eggs must remain suspended in the water column in order to hatch successfully. Using sand, the effects of varying sediment levels on grass carp eggs were tested at different developmental states and temperatures. Survival was high (15–35%, depending on temperature and trial) in the unburied treatment where eggs rested on a sand bed but were not covered by sediment. Survival was lower in the partial burial (5–10%) and very low (0–4%) in the full burial treatment. In all treatments, delayed hatching (organisms remaining in membranes past the stage of hatching competence) was noted. Deformities such as missing heads and pericardial edema occurred at high rates in the partial and full burials. Eggs that come in contact with the benthos and are resuspended in the water column should be considered in embryonic drift models.

Mechanical Properties and Biodegradability of Acid-soluble Chitosan-Starch Based Film

Chitosan-starch blend film showed desirable elongation and oxygen transmission rate (OTR) values and demonstrated rapid degradation in soil burial treatment. The incorporation of higher glycerol concentration lowered tensile strength but increased the amount of transmittable water vapour. The biodegradability of chitosan-starch based film was tested using soil burial test. Chitosan-starch blend films were able to degrade naturally at slightly similar period, ranging from 72–87 days. The addition of glycerol was likely contributed to the high Water Vapour Transmission Rate (WVTR) value which faster the biodegradability of the film in soil. Among different type of acid solutions, lactic acid is less preferable solution to dissolve chitosan as it produced film with poor mechanical properties compared to acetic and formic acid. Based on its mechanical limitation, the film can be used as a coating based film for certain type of fish product, especially product with high lipid content.

Surveillance and Outbreak Response Management System (SORMAS) to support the control of the Ebola virus disease outbreak in West Africa

In the context of controlling the current outbreak of Ebola virus disease (EVD), the World Health Organization claimed that 'critical determinant of epidemic size appears to be the speed of implementation of rigorous control measures', i.e. immediate follow-up of contact persons during 21 days after exposure, isolation and treatment of cases, decontamination, and safe burials. We developed the Surveillance and Outbreak Response Management System (SORMAS) to improve efficiency and timeliness of these measures. We used the Design Thinking methodology to systematically analyse experiences from field workers and the Ebola Emergency Operations Centre (EOC) after successful control of the EVD outbreak in Nigeria. We developed a process model with seven personas representing the procedures of EVD outbreak control. The SORMAS system architecture combines latest In-Memory Database (IMDB) technology via SAP HANA (in-memory, relational database management system), enabling interactive data analyses, and established SAP cloud tools, such as SAP Afaria (a mobile device management software). The user interface consists of specific front-ends for smartphones and tablet devices, which are independent from physical configurations. SORMAS allows real-time, bidirectional information exchange between field workers and the EOC, ensures supervision of contact follow-up, automated status reports, and GPS tracking. SORMAS may become a platform for outbreak management and improved routine surveillance of any infectious disease. Furthermore, the SORMAS process model may serve as framework for EVD outbreak modeling.

海滨滨麦叶片和根对不同厚度沙埋生理响应差异分析

PDF HTML阅读 XML下载 导出引用 引用提醒 海滨滨麦叶片和根对不同厚度沙埋的生理响应差异分析 DOI: 10.5846/stxb201312172966 作者: 作者单位: 鲁东大学生命科学学院 山东烟台 264025,鲁东大学生命科学学院 山东烟台 264025,鲁东大学生命科学学院 山东烟台 264025,鲁东大学生命科学学院 山东烟台 264025,鲁东大学生命科学学院 山东烟台 264025,鲁东大学生命科学学院 山东烟台 264025 作者简介: 通讯作者: 中图分类号: 基金项目: 烟台市科技局资助课题(2013ZH351);国家973课题(2009CB421303);国家自然科学基金项目 (30972422) Analysis of the different physiological responses of Leymus mollis (Trin.) Hara leaves and roots to sand burial on the coast of Yantai, China Author: Affiliation: Ludong University,Ludong University,Ludong University,Ludong University,Ludong University,Ludong University Fund Project: 摘要 | 图/表 | 访问统计 | 参考文献 | 相似文献 | 引证文献 | 资源附件 | 文章评论 摘要:以烟台海岸抗风沙植物滨麦为研究材料,通过对不同厚度沙埋下其叶片和根部抗氧化酶活力(超氧化物歧化酶(SOD)、过氧化物酶(POD)、 过氧化氢酶(CAT))、丙二醛(MDA)含量和渗透调节物含量变化的分析,探讨了叶片和根部对沙埋生理响应的差异。 试验按滨麦成株株高(约40 cm)对其进行了轻度沙埋(在株高1/4 处)、中度沙埋(2/4 处)和重度沙埋(3/4 处)。在沙埋第6天,分别测定了不同厚度沙埋处理下,植株各段叶片和根抗氧化酶活力、MDA和渗透调节物含量。结果表明,轻度和中度沙埋均加速植株生长。与对照相比,经轻度、中度沙埋处理6 d,叶片平均MDA含量增加,在重度沙埋下降低。不同厚度沙埋6 d, 叶片平均SOD活力和脯氨酸含量增加, 而CAT活力、可溶性糖和可溶性蛋白质含量下降。 但不同厚度沙埋均使沙上叶片MDA、脯氨酸、可溶性蛋白质含量和SOD和CAT活力增加,尤其是叶片顶部增加最为明显,使沙下叶片MDA、可溶性糖、可溶性蛋白质含量和CAT活力下降,导致同株沙上和沙下叶片MDA、脯氨酸、可溶性糖、可溶性蛋白质含量和SOD和CAT活力差异显著(P<0.05)。与叶片相比,根中MDA、可溶性蛋白质含量和SOD和CAT活力较低, 而POD活力和可溶性糖含量较高并与叶片差异显著(P<0.05)。不同厚度沙埋6 d,滨麦根中MDA和可溶性蛋白质含量变化较小,可溶性糖含量和CAT、POD、SOD活力略有降低。研究表明,滨麦根和叶片对不同厚度沙埋的生理响应不同。沙埋直接作用于叶片并诱发叶内氧自由基积累,但叶片通过快速激活的抗氧化酶保护系统(CAT、SOD)维持氧自由基代谢平衡,以及渗透调节物(脯氨酸、可溶性糖)的积累维护细胞水分代谢平衡,并满足能量的需求和快速生长。但在不同厚度沙埋下,由于根系不受沙埋直接影响而生理变化较小,并且还维持较低的膜脂过氧化水平,这可能是根能维持正常的吸水输水功能并在沙埋处理过程中和沙埋后地上叶片快速生长摆脱沙埋的重要物质基础。 Abstract:In this study, we tested the physiological responses of Leymus mollis (Trin.) leaves and roots to sand burial on the Yantai coast of China to understand the biochemical and physiological adaptive mechanisms of this species to sand burial. Based on the height of L. mollis (about 40 cm) four levels of sand burial treatments were set up: no-sand burial (control), light sand burial (1/4 plant height), moderate sand burial (1/2 plant height), and severe sand burial (3/4 plant height). After 6 days of sand burial, samples were taken from the leaves and roots of plants in each treatment. Changes in malonaldehyde (MDA) content, an osmotic regulator, in addition to antioxidant enzymes superoxide dismutase (SOD), peroxidase (POD), and catalase (CAT) activity, were measured in the leaves above and below the sand and in the roots at various depths. Plants under light and moderate sand-burial grew fast until they protruded from the sand, becoming taller than control plants after 6 days. Compared to the control, the average MDA content increased in whole leaves under light and moderate sand burial, but and decreased in leaves subject to severe sand burial. In all three sand burial treatments, SOD activity and proline content increased in whole leaves, whereas CAT activity and soluble sugar and soluble protein contents decreased. In all three burial treatments, MDA, proline, and soluble protein content increased in leaves above the sand, along with SOD and CAT activity, especially in the top section of the leaves. In contrast, MDA, soluble sugar, and soluble protein content, in addition to CAT activity, decreased in the leaves beneath the sand. This resulted in significant differences in MDA, proline, soluble sugar, and soluble protein content, in addition to SOD and CAT activity, between leaves above and below the sand (P< 0.05). Compared to above ground leaves, underground roots had lower MDA and soluble protein content, in addition to lower SOD and CAT activity, but higher POD activity and soluble sugar content. After 6 days of sand burial, there was a small change in MDA and soluble sugar content, with soluble sugar content and CAT, POD, and SOD content slightly decreasing in the roots. On the same plant, leaves above ground had significantly higher (P<0.05) MDA and soluble protein content, along with higher CAT and SOD activity, than the underground roots. This result indicates that sand burial had a greater effect on the aboveground structures (branches and leaves) above ground compared to the underground structures. Sand-burial caused the accumulation of oxygen free radicals in the cells, which induced lipid peroxidation and activated the antioxidant enzymatic protection system to scavenge oxygen free radicals and maintain the metabolic balance of oxygen free radicals. This action also promoted osmotic adjustments to maintain the balance of water metabolism and provide energy and nutrition. Thus, under sand burial, it may be important to enhance cell antioxidant and osmotic adjustment capacity rapidly to maintain the balance of oxygen free radical metabolism and metabolic water balance, a key physiological regulation strategy for L. mollis for sand burial adaptation. Moreover, the root system was not affected by the different levels of sand burial, and continued to sustain lower levels of lipid peroxidation, allowing the roots to maintain normal functions of water suction and transportation, and to support the fast growth of leaves out of the sand. 参考文献 相似文献 引证文献

Effects of experimental stem burial on radial growth and wood anatomy of pedunculate oak

In dendrogeomorphology, abrupt changes in wood anatomy are frequently used to date the exact year of burial and exposure events. However, few studies have addressed the precision and underlying mechanisms of these changes. In a field experiment, performed in a drift-sand area in the Netherlands, we buried the stems of mature pedunculate oak trees (Quercus robur L.) up to a height of 50cm and analysed the responses in ring width and earlywood-vessel characteristics, while monitoring the course of temperature above and below the soil surface.After 3 years of stem burial, we found no significant differences in ring width and earlywood-vessel characteristics between control and buried trees both above and below the burial level. Burial however strongly reduced temperature amplitude and the occurrence of sub-zero temperatures around the buried stems. All buried trees formed epitropic roots that grew upward into the new sediment layer, but no adventitious roots were formed on the buried stems. Irrespective of the burial treatments, we found that the mean ring width was largest at the original stem base and lowest at breast height. In contrast, vessel sizes were significantly larger at breast height compared with the stem base. Differences in vessel density barely differed between years and heights.In our field experiment on mature pedunculate oak trees, the burial of stems by 50cm of drift sand did not induce any local growth suppression or detectable changes in wood anatomy. As wood-anatomical changes in response to burial have previously been reported for trees that had formed adventitious roots, we stress the role of adventitious-root formation as a possible trigger behind the local changes in wood anatomy, reflecting a functional change of a buried stem towards a root. Based on our field experiment, it seems unlikely that years of shallow or moderate burial events (≤50cm) can be reconstructed using the wood structure of buried stems. As epitropic roots develop quickly after burial, dating such roots may potentially yield better estimates of burial events. Further research on the relation between adventitious root and changes in stem anatomy is needed to ascertain the precision of dating sand-burial events using tree rings.

海滨沙地单叶蔓荆匍匐茎对沙埋适应生长对策

PDF HTML阅读 XML下载 导出引用 引用提醒 海滨沙地单叶蔓荆匍匐茎对沙埋适应的生长对策 DOI: 10.5846/stxb201305030911 作者: 作者单位: 鲁东大学生命科学学院,鲁东大学生命科学学院 作者简介: 通讯作者: 中图分类号: 基金项目: 国家973课题(2009CB421303);国家自然科学基金项目(30972422);山东省高校科技计划(J10LC02) Analysis on the growth strategy of creeping stem in Vitex trifolia var.simplicifoli adapting to sand burial Author: Affiliation: School of Life Science,Ludong University,Yantai,School of life science, Lu Dong University Fund Project: 摘要 | 图/表 | 访问统计 | 参考文献 | 相似文献 | 引证文献 | 资源附件 | 文章评论 摘要:单叶蔓荆(Vitex trifolia var.simplicifoli)是一种耐盐、耐旱固沙地被植物。依据海滨沙地自然沙埋特点对单叶蔓荆匍匐茎进行了不同厚度(半埋和全埋)和不同长度交叉沙埋处理,研究探讨了单叶蔓荆沙埋适应生长对策, 为其开发利用、科学管理和海滨环境修复提供指导。结果表明,正常情况下,单叶蔓荆匍匐茎基部和中部生长缓慢,顶部生长快。轻度(沙埋匍匐茎基部)和中度(沙埋匍匐茎基部和中部)半埋和全埋使匍匐茎顶部生长加速,茎长增长量较对照高出1.5到3.1倍;但重度(沙埋整个匍匐茎)半埋和全埋使匍匐茎顶部净增长量减少12% 和13%。在20d沙埋中,对照整个匍匐茎各段均无不定根长出,但不同程度半埋和全埋沙埋处理下沙下匍匐茎上均长出不定根,重度半埋使不定根生长受抑;同时匍匐茎上各段茎生物量上升,枝叶生物量下降, 且随着沙埋程度的增加而增减幅度提高,在重度半埋和全埋达到最大。在轻度和中度半埋和全埋下,匍匐茎上未沙埋部位枝条生长加速。研究表明,在自然环境中,单叶蔓荆匍匐茎顶端是一个对环境变化反应敏感的部位,并与沙埋后单叶蔓荆茎延伸生长和植株能否生存密切相关。当匍匐茎顶部没被沙埋时,沙埋促进沙埋部位匍匐茎和枝叶中物质转移,加速匍匐茎顶部快速生长和物质积累以弥补沙埋带来的损伤维持物质和能量的代谢平衡。沙埋后,单叶蔓荆以茎顶端快速生长、形成不定根、枝条生长维持茎水分平衡和能量和物质代谢平衡, 以快速生长摆脱沙埋影响的生长方式为其对沙埋环境的重要适应对策。因此,在海岸沙地单叶蔓荆种群管理和维护中,在强风移沙引起的重度沙埋后, 及时剥离匍匐茎顶部沙子对维护单叶蔓荆种群的延续生存和扩散均有重要作用。 Abstract:Vitex trifolia var. simplicifolia is a good ground cover plant and sand binder for coastal sandy land; it has a high tolerance for salt and drought and, in its natural environment of sand dunes, it is often buried by blowing sand. In these experiments, basis on the stolon length of V. trifolia, the four level of sand burial treatments were set up as no-sand burial, light sand burial (1/3 stolon length), moderate sand burial (2/3 stolon length) and severe sand burial (3/3 stolon). The different lengths of stolon were buried to two different depth, to half the plant height or to the full plant height, to show how the plant maintained growth under different levels of sand burial. Plant height, lengths of stolon and adventitious roots, the ratio of stolon dry weight (DW) to total DW, and the ratio of shoot and leaf DW to total DW were recorded. Normally, stoloniferous base and middle section of V. trifolia grow slowly, the top of the stolon grew fast . The results showed that during 20d treatments, there was little difference in the growth of stolon from the basal area to the middle section of the stolon between the control (4.1cm) and light and moderate sand burial groups (4.5 cm). However, there was larger difference in the growth of top of the stolon between control and half and full of the light and moderate sand burial groups. At top of the stolon, the stolon was longer 1.5 to 3.1 times in plant under half and full of the light and moderate sand burial groups than that in the control. While length of top of the stolon under half and full of severe sand burial was shorter by 12% and 13% than that in the control, because apical section were covered. In 20d, many adventitious roots were observed in the stolon under half and fall light and moderate sand burial but not in the control; adventitious roots were also limited in plants under half and full severe sand burial. At the same time, the ratio of stolon DW to total DW increased, peaking at half and full severe sand burial; the ratio of shoot and leaf DW to total DW decreased with increasing of sand burial level. This study indicates that the apex of the stolon of V. trifolia is important to growth and plant survival under sand burial. When sand burial did not include the apex of the stolon, adventitious roots were produced along the stolon under half and full light and moderate sand burial. Those new adventitious roots helped plants to absorb more water and nutrients from soil to maintain water balance of shoot, and to support the shoot growing up. Growth fast of top of the stolon and produced adventitious roots maybe a key for V.trifolia to avoid being further covered by sand. When the full plant was covered with sand under half and full sever sand burial, the strategy of the plant in adapting to sand burial was that leaves under sand died and the material in the leaves was transferred to the apex of the stolon; however longer full sand burial results in death of the plant. 参考文献 相似文献 引证文献

小叶锦鸡儿抗沙埋生长与抗氧化酶及同工酶变化的关系

PDF HTML阅读 XML下载 导出引用 引用提醒 小叶锦鸡儿抗沙埋生长与抗氧化酶及同工酶变化的关系 DOI: 10.5846/stxb201306131701 作者: 作者单位: 鲁东大学,鲁东大学，生命科学学院,鲁东大学，生命科学学院,鲁东大学，生命科学学院,鲁东大学，生命科学学院,鲁东大学，生命科学学院 作者简介: 通讯作者: 中图分类号: 基金项目: 国家重点基础研究发展计划(2009CB421303); 国家自然科学基金项目(30972422); 中国科学院方向性项目(KZCXZ-YW-431) The relationship between growth of Caraganas stenophylla and the activities and isoforms of protective enzymes under different depths of sand burial Author: Affiliation: College of Life Sciences, Ludong University,,,,, Fund Project: 摘要 | 图/表 | 访问统计 | 参考文献 | 相似文献 | 引证文献 | 资源附件 | 文章评论 摘要:小叶锦鸡儿(Caraganas tenophylla L.)是广泛应用于流动沙丘治理的优良固沙植物。然而关于其抗沙埋生理机理目前尚不清楚。选择生长在科尔沁沙地的小叶锦儿为试验材料,依据株高对其进行不同程度沙埋(轻度、中度、重度沙埋), 并通过测定沙埋过程中植株高度、不同部位叶片丙二醛(MDA)含量、抗氧化酶活力、抗氧化酶同工酶谱变化, 以揭示其抗沙埋生理适应机理和基因调控机理。结果表明:沙埋6d,植株各部位生长加快,尤其是顶部和基部生长更快。叶片MDA含量降低、整株植物叶片平均过氧化氢酶(CAT)、过氧化物酶(POD)、过氧化物歧化酶(SOD)活力增加,但重度沙埋使抗氧化酶活力下降。沙埋12d,植株各部位生长继续加大, 沙下叶片凋落。与对照相比,沙上叶片MDA含量成倍增加,并与叶片POD、SOD和CAT活力的大幅度提高呈正相关,并与对照差异显著(P < 0.01)。同时,不同厚度沙埋6d,叶片CAT同工酶出现两新带CAT III和CATII;POD同工酶谱带(6条酶带)随沙埋厚度增加,叶片PODII区带加宽、色加深,POD I 和POD III酶带消失。但是,不同厚度沙埋下,沙上和沙下叶片CAT、SOD和POD酶谱带数和活力均相同。这表明在沙埋应激适应反应期(6d),叶片抗氧化酶活力的增强与抗氧化酶基因表达增强和基因启动有关。受到沙埋重力胁迫的成熟叶可能将胁迫信号传递给沙上没有沙埋的叶子及生长点,导致整株叶片产生整体适应性反应,激活抗氧化酶系统,以致加速生长。因此,小叶锦鸡儿萌蘖生物学特性和抗氧化酶对沙埋胁迫快速响应在维护氧自由基代谢平衡和植株快速恢复生长中起重要保护作用。 Abstract:The shrub Caraganas stenophylla is widely distributed and used as a sand binding plant on moving sand dunes in China. The physiological mechanisms involved in C. stenophylla responds to coverage with sand are unknown. Therefore we investigated responses to three levels of sand burial based on plant height: light (1/4 plant height), modest (2/4 plant height), and severe (3/4 plant height) as compared with controls (no sand burial). To understand the physiological and molecular regulatory mechanisms for C. stenophylla in adaption to sand burial, changes in length of different parts of plant stems were observed 3 days (d), 6d, 9d, and 12d after sand burial treatment and contents of malondialdehyde (MDA) and activities of antioxidant enzymes peroxidase (POD), catalase (CAT), and superoxide dismutase (SOD) were measured 6d and 12d after treatment. CAT and POD isozymes were also analyzed in leaves 6d after sand burial treatment. Results showed that 6d after sand burial treatment, growth rates of different parts of the stem increased as burial deepened. At the same time, MDA content in the leaves decreased and activities of CAT, POD and SOD in different plant parts increased under light and modest sand burial treatments. Growth rate was higher 12d after treatment than at 6d after treatment but the leaves under sand died. Meanwhile, MDA content and SOD activity were markedly increased by 64% and 121% in leaves above sand under modest and severe sand burial. CAT activity in leaves above sand was also higher under light and modest sand burial. POD activity in the leaves under different depths of sand burial was higher by 308%-104%. SOD activity was higher by 32% and 233% in the leaves with modest and severe sand burial compared with controls. This suggests that the higher growth rate during 7-12d was positively correlated with higher activities in protective enzymes, and increases in antioxidant capacity after sand burial, which might have played an important role in the stem growth and the balance of oxygen free radical metabolism. Analysis of isomers of antioxidant enzymes by native-PAGE and activity staining revealed new isoforms, CAT III and CATII, in the leaves with modest and severe sand burial, and their concentrations were enhanced by sand burial. There are six isoforms of POD; POD II intensity increased with increasing depth of sand burial; a new band, POD IV, was observed while POD I and POD III disappeared. This suggests that during acclimation to sand burial, the activity of protective enzymes is highly related to differential gene expression. Isofo rms of CAT, POD and SOD in the leaves over sand were similar to those under sand 6d after sand burial, which indicates that the signal of sand burial was transduced from leaves under sand to leaves over sand, resulting in the whole plant receiving the signal of sand stress to adapt to sand burial. Therefore, differential gene expression plays an important role in increasing protective enzyme activity to maintain the balance of oxygen free radical metabolism in C. stenophylla. 参考文献 相似文献 引证文献

Germinación y ruptura de latencia en semillas de Daphne giraldii Nitsche (Thymelaeaceae) provenientes del noroeste de China

Daphne giraldii Nitsche (Thymelaeaceae) es un arbusto de hoja perenne utilizado ampliamente como planta ornamental y en la industria farmacéutica de China. La planta exhibe latencia que retrasa y reduce la germinación. Este estudio determinó los efectos del tratamiento químico, la estratificación y el tratamiento de siembra de semillas para interrumpir la latencia de D. giraldii. Los resultados mostraron que el pretratamiento químico fue el menos eficaz. El mejor porcentaje de germinación (GP) fue 52.33 % y solamente se observó una tasa de germinación (GR) de 1.19 después de 70 días de la estratificación de semillas a una temperatura de 5 °C. Esto indica que el comportamiento de la germinación de D. giraldii no se vio afectado significativamente por la estratificación. La latencia fisiológica de semillas de D. giraldii se mitigó durante la siembra de semillas. Las semillas enterradas a 100 cm de profundidad por 170 días germinaron exitosamente con 86.5 % e índice de germinación de 10.11, por lo que fue el tratamiento más eficaz para mitigar la latencia de las semillas. Esta información puede ser útil para restaurar y conservar otros arbustos que crecen en el noroeste de China y dilucidar su supervivencia en condiciones extremas similares.

Governing from the Grave: Vampire Burials and Social Order in Post-medieval Poland

Mortuary treatments are ways in which archaeologists can learn about the culture and lifestyle of past societies, in terms of how they view the dead. The dead, however, can continue to play a role in the lives of the living, which may also be reflected in funerary rites and burial treatments. This article explores the social agency of the dead, focusing on the ‘vampire burials’ of the post-medieval Polish site of Drawsko 1. These burials, identified through their grave goods, provide a unique opportunity to learn how vampire folklore and the deceased ‘vampires’ influenced the living, most notably as ways to encourage social order, as an explanation for the unknown, and as an economic commitment.

High water level impedes the adaptation of Polygonum hydropiper to deep burial: responses of biomass allocation and root morphology.

Many studies have investigated the individual effects of sedimentation or inundation on the performance of wetland plants, but few have examined the combined influence of these processes. Wetland plants might show greater morphological plasticity in response to inundation than to sedimentation when these processes occur simultaneously since inundation can negate the negative effects of burial on plant growth. Here, we evaluate this hypothesis by assessing growth of the emergent macrophyte Polygonum hydropiper under flooding (0 and 40 cm) and sedimentation (0, 5, and 10 cm), separately and in combination. Deep burial and high water level each led to low oxidation-reduction potential, biomass (except for 5-cm burial), and growth of thick, short roots. These characteristics were generally more significant under high water level than under deep burial conditions. More biomass was allocated to stems in the deep burial treatments, but more to leaves in the high water level treatments. Additionally, biomass accumulation was lower and leaf mass ratio was higher in the 40-cm water level + 10-cm burial depth treatment than both separate effects. Our data indicate that inundation plays a more important role than sedimentation in determining plant morphology, suggesting hierarchical effects of environmental stressors on plant growth.

Effects of continual burial by sediment on morphological traits and dry mass allocation of Suaeda salsa seedlings in the Yellow River estuary: An experimental study

Information on the effects of continual burial by sediment on seedling survival and morphological growth in coastal marsh remains scarce. A greenhouse experiment was conducted to determine the effects of continual burial on seedling mortality, growth and dry mass allocation of Suaeda salsa in the coastal marsh of the Yellow River estuary. The seeds were planted at 0.5cm depth in plastic pots filled with unsterilized sediment on May 5, 2012. A depth of 8cm was chosen as the maximum of continual burial according to the sedimentary rate (6–7cm) in the coastal marsh at seedling stage. Two weeks after emergence, seedlings were artificially buried to depths of 0 (D0, no burial), 33% (D33, burial of 1mmd−1), 67% (D67, burial of 2mmd−1), 100% (D100, burial of 3mmd−1) and 133% (D133, burial of 4mmd−1) of their mean height, with 20 days in total. Results showed that seedling height, stem and taproot diameter, number of branch, hypocotyl and taproot length, and dry mass were significantly affected by burial depth (p<0.05). No seedlings died in the four burial treatments. Seedling heights in the D33 and D67 treatments were higher than those of the other treatments, indicating that shallow and moderate burials exhibited greater stimulation to seedling growth. Although stem diameter, number and length of branch, and dry mass of seedlings were stimulated in the four burials, the greatest stimulatory effect on stem diameter was observed in the D100 treatment while that on number and length of branch and dry mass occurred in the D67 treatment. With increasing burial depth (D67, D100 and D133), seedling taproot diameter and length decreased while hypocotyl length increased, reflecting that hypocotyl elongation might occur at the expense of development of the root system. The responses of morphological traits and dry mass allocation of S. salsa seedlings to the burial treatments indicated that they might have a special strategy to tolerate the continual burial in the coastal marsh of the Yellow River estuary. The use of thin-layer burial (2mmd−1) to promote seedling vigor in degraded S. salsa marsh was feasible, and our study provided valuable information for the restoration of S. salsa marsh during seedling growth.

差巴嘎蒿幼苗对沙埋的生态适应和生理响应

PDF HTML阅读 XML下载 导出引用 引用提醒 差巴嘎蒿幼苗对沙埋的生态适应和生理响应 DOI: 10.5846/stxb201301210125 作者: 作者单位: 中国科学院寒区旱区环境与工程研究所,鲁东大学生命学院,鲁东大学生命学院,鲁东大学生命学院 作者简介: 通讯作者: 中图分类号: 基金项目: 国家自然科学基金项目（31270752，30972422） Ecological adaptation and physiological response of Artemisia halodendron seedling to sand burial Author: Affiliation: Cold and Arid Regions Environment and Engineering Institute,CAS,Lanzhou,Faculty of Life Sciences,Ludong University,Yantai,Faculty of Life Sciences,Ludong University,Yantai,Faculty of Life Sciences,Ludong University,Yantai Fund Project: 摘要 | 图/表 | 访问统计 | 参考文献 | 相似文献 | 引证文献 | 资源附件 | 文章评论 摘要:沙埋对于沙漠植物存活和生长影响的研究文献已有很多，但迄今有关沙漠植物对于沙埋生理生态适应的研究还很少见有报道。差巴嘎蒿（Artemisia halodendron）广泛分布于我国半干旱沙地中，是流动半流动沙地的优势种。为了解沙生植物对沙埋的生态适应及其生理响应，2010-2011年在内蒙古科尔沁沙地研究了不同沙埋深度下差巴嘎蒿幼苗的存活率、株高等生长特性和渗透调节物质含量，保护酶活性和膜透性的变化，得到以下结果：沙埋对差巴嘎蒿幼苗的存活与生长有着显著影响，特别是沙埋深度超过其株高后，其存活率和高生长受到严重抑制，但和非沙生植物相比，差巴嘎蒿幼苗具有很强的耐沙埋能力，即使沙埋深度达到其株高的200%时仍有部分幼苗存活。随着沙埋深度的增加，差巴嘎蒿幼苗叶片含水量没有显著变化，但过氧化物歧化酶活力降低，过氧化物酶活性增强，过氧化氢酶活性变化不明显，脯氨酸含量增加，可溶性糖含量下降，丙二醛含量下降，膜透性增强。和水分、盐分胁迫不同，沙埋并未造成差巴嘎蒿幼苗的水分亏缺，沙埋胁迫下差巴嘎蒿幼苗死亡率增加、生长受到抑制的主要原因是沙埋导致植物光合面积下降，沙埋叶片无法进行正常呼吸和部分幼苗无法破土生长，但沙埋胁迫下脯氨酸含量的和过氧化物酶活性增强分别在渗透调节和保护细胞膜免受损伤中起到了关键作用。 Abstract:There is a great deal of literatures on the effects of sand burial upon the survival and growth of desert plants, but the physiological and ecological adaption of desert plants to sand burial have as yet rarely been studied. Artemisia halodendron is widely distributed in the semiarid deserts of China and is a dominant species in semi-moving dune vegetation. In order to understand the ecological and physiological adaptation of prammophytes to sand burial,,changes of survival rate, plant height, biomass, osmotic regulation substances, protective enzymes and membrane permeability of A. halodendron in different sand burial depths were studies during 2010-2011 in the Horqin Sand Land of Inner Mongolia. The experiment included ten burial treatments: buried to 0% (CK, no burial), 25% (A), 50% (B), 75% (C), 100% (D), 125% (E), 150% (F), 175% (G) and 200% (H) and 225%(I) of seedling height. The results showed that 1) A. halodendron had a stronger ability to withstand sand burial stress, with some plants still surviving even if buried to a depth reaching 200% of the seedling heights. Although seedling growth was inhibited significantly once the depth of sand burial reached 50% of seedling height, seedling survive did not decrease significantly until the burial depth exceeded 100% of seedling height; 2) MDA content was significantly lower in the partial sand burial treatments compared to CK, but membrane permeability did not increase significantly. After being subjected to complete sand burial, MDA content was still lower in most the treatments compared to CK, while membrane permeability increased significantly. Sand burial did not produce water stress in the seedlings, a major mechanism causing decreased MDA content is that the darkness, hypoxia and low temperature inhibit production of oxygen free radicals and membrane lipid peroxidation; 3) Compared with CK, SOD activity was significantly lower in all sand burial treatments except for treatments D and H, POD activity was higher in all sand burial treatments except treatment D, and CAT activity showed no significant changes with any of the sand burial treatments except for being elevated in treatments C and D. In general, POD activity increased when the activities of SOD and CAT decreased, and SOD and CAT activities increased when POD activity decreased. MDA content had a positive correlation with SOD and POD and a negative correlation with CAT. These results suggested that although there was a complementary interplay among the three enzymes, POD played a central role and SOD and CAT played supporting roles in scavenging active oxygen and minimizing cell membrane damage; 4) When subjected to partial burial with sand, proline content showed no significant changes and the soluble sugar content decreased significantly compared to CK. After sand burial exceeded the seedling height, proline content increased significantly; although soluble sugar content increased, the difference from CK did not reach a significant level. The results suggested that when subjected to the severe stress of sand burial, proline plays a major role and soluble sugar fails to play an effective role in the osmotic adjustment process. 参考文献 相似文献 引证文献

Early Bronze Age burial customs on the central Anatolian plateau: a view from Demircihöyük-Sarıket

AbstractThis paper focuses on the analysis of the cemetery of Demircihöyük-Sarıket, for which exists one of the largest Early Bronze Age funerary datasets published to date in Anatolia. The size and quality of the sample allow the dataset to be approached quantitatively, to determine both normative and anomalous funerary practices, and to detect distinct patterns of burial treatment for different segments of the population represented in the cemetery. Despite the small size of the community (ca 100–130 people), the results suggest a rather complex picture, in which the choice of specific burial containers, the relative wealth of grave assemblages and the selection of particular sets of items were dependent on differences in the age, gender, occupation and achieved status of the deceased. Comparison with other contemporary funerary assemblages helps to place Demircihöyük-Sarıket and these community-scale observations within their wider cultural context in central Anatolia.

Effects of wind erosion and sand burial on water relations and photosynthesis in Alhagi sparsifolia in the southern edge of the Taklimakan Desert

Aims The objectives of this study were to investigate the effects of disturbance through wind erosion and sand burial on water relations and photosynthesis in Alhagi sparsifolia, and to determine the best habitat for the growth of A. sparsifolia in the southern edge of the Taklimakan Desert. Methods We set up five treatments, including wind erosion depth of 10 cm, wind erosion depth of 5 cm, control, sand burial depth of 10 cm, and sand burial depth of 30 cm. Measurements were made on the concentration of photosynthetic pigments, chlorophyll fluorescence parameters, leaf water potential, and leaf water content in A. sparsifolia under different treatments on a sunny day. Important findings Leaf water potential and leaf water content in A. sparsifolia m significantly decreased following the wind erosion treatments, thereby causing a reduction in the stomatal conductance, which in turn resulted in declining photosynthetic rate and transpiration rate. The water use efficiency in plants under the wind erosion treatments was lower than that under the sand burial condition, especially in the treatment of wind erosion depth of 10 cm. In addition, leaf water potential and leaf water content in A. sparsifolia were higher in the sand burial treatments than in the wind erosion treatments, which were associated with higher values of stomatal conductance, photosynthetic rate, transpiration rate, and water use efficiency. The maximum photochemical efficiency(Fv/Fm) in A. sparsifolia was suppressed under the wind erosion treatments, indicating increased stress suffered by the plants. However, A. sparsifolia may resist the adverse effects of wind erosion through increases in the number of active reaction centers and photochemical efficiency. The Fv/Fm in A. sparsifolia was higher under the sand burial treatments, indicating that the stress of A. sparsifolia suffered was alleviated. The absorption of lightquantum yield and energy used for the photochemical reaction in the reaction center decreased increasing sand burial depth. This might be a survival strategy that A. sparsifolia adopted in response to the severe wind-blown sand environment. Compared with those in the treatments of wind erosion depth of 5 cm and sand burial depth of 10 cm, the growth of A. sparsifolia plants was significantly inhibited in the treatment of wind erosion depth of 10 cm, and significantly enhanced in the treatment of sand burial depth of 30 cm.

Negative influence of burial stress on plant growth was ameliorated by increased plant density in Polygonum hydropiper

Abstract Sedimentation and density are important factors influencing the growth of wetland plants. The aim of this study was to elucidate the role of plant density in acclimation to burial stress by investigating the growth, biomass allocation, and carbohydrate contents of Polygonum hydropiper L. var. flaccidum , one of the dominant species in the Dongting Lake wetland, China. Experimental treatments, conducted in a greenhouse, combined three plant densities (16, 144, and 400 plants m −2 ) with two burial depths (0 and 15 cm) in a factorial design. Greater burial depth and higher plant density had negative effects on biomass accumulation and plant height with some exceptions. Plant growth, although lower at higher densities in general, was unaffected by burial depth at medium and high densities, indicating that the negative effect of burial stress was ameliorated by increased plant density. Deeper burial led to higher stem mass fraction only in the low-density treatment. Belowground mass fraction increased significantly with increasing density in both burial treatments. Moreover, higher density and deeper burial led to higher soluble sugar content but lower starch content. These data indicate that higher density facilitates acclimation of P. hydropiper to burial stress through increased soluble sugar content.

Sand burial compensates for the negative effects of erosion on the dune-building shrub Artemisia wudanica

AimsPlant species response to erosion or burial has been extensively studied, but few studies have examined the combined effects of erosion and subsequent burial on plants. In active sand dunes of northern China, Artemisia wudanica falls to the ground following wind erosion, accumulating sand among fallen stems in a process that may facilitate its further growth and development. Therefore, we hypothesize that subsequent sand burial might compensate for the negative effects of erosion in the growth of A. wudanica.MethodsA common garden experiment was conducted using A. wudanica seedlings to evaluate their growth in response to different degrees of burial and erosion as observed at the field. Seedlings were selected and randomly assigned to six erosion treatments, two burial treatments, twelve erosion and subsequent burial treatments, and control. Each treatment was replicated six times.ResultsCompared with the control treatment, total biomass and the relative growth rate of shoots were stimulated in the erosion and subsequent burial treatments (significantly under the 10 cm burial), hampered in erosion only treatments, and were not affected in the burial only treatments. Adventitious roots and ramets were only observed under burial only and erosion and subsequent burial treatments.ConclusionsOur results indicate that subsequent sand burial following erosion compensate for the negative effects of erosion on the growth of A. wudanica seedlings, and greatly contributed to their tolerance to wind erosion.

Survivorship and longevity of Diamesa mendotae Muttkowski (Diptera: Chironomidae) under snow

&lt;em&gt;Diamesa mendotae&lt;/em&gt; Muttkowski commonly grow and emerge from groundwater dominated streams in winter. Previous estimates of longevity for adults of &lt;em&gt;D. mendotae &lt;/em&gt;collected from the snow surface averaged 18.6 days post-collection, with 76.9% of individuals dying between Day 10 and Day 30 post-collection and 4.4% surviving over 40 days. Maximum longevities for males and females were 48 and 54 days, respectively. In this paper, we report survivorship and longevity of fieldcollected adults of &lt;em&gt;D. mendotae&lt;/em&gt; kept at ambient snow temperature conditions. Adults (n=140) were collected in February from snow along groundwater-dominated sections of the Kinnickinnic River (Wisconsin, USA). All individuals were placed in vials, buried in snow, and retrieved in batches of 10 males and 10 females at 4-day intervals for 28 days. Once retrieved, adults were maintained at 6&amp;deg;C in controlled environmental chambers to determine survivorship and longevity. All individuals survived snow burial treatment, indicating they are capable of surviving sub-freezing field conditions for at least 28 days. Estimates of adult maximum longevity were as high as 66 days, higher than previous estimates for this genus. Our results suggest adults of &lt;em&gt;D. mendotae&lt;/em&gt; can persist under snow cover, with high survivorship and longevity, potentially increasing their probability of successful reproduction in regions where lethal winter air temperatures occur.

Accommodation space limits plant invasion: Ammophila arenaria survival on New Zealand beaches

Ammophila arenaria (marram grass) may invade remote beach-dune systems by the marine dispersal of rhizomes. In New Zealand, and elsewhere, the conservation of the remaining dune systems of high conservation value would be advanced by predicting where this species might successfully establish and undertaking appropriate surveillance. This paper examines the ability of A. arenaria to sustain growth in the stressful back-beach environment. Shoots developed from rhizomes were subjected to burial, depth, salt spray and desiccation treatments in the glasshouse. Plants were also subjected to salt water inundation. Two field populations of A. arenaria were surveyed for a period of almost 3 years, following rhizome stranding in July 2007. Shoots were able to emerge from depths of up to 40 cm. Rhizomes failed to produce shoots when the moisture content of rhizomes was less than 18.25 %, which occurred after 3 days of drought. The survival of buried plants was significantly reduced compared to non-buried plants when burial exceeded 80 % of the plant height. No plants survived when burial exceeded 100 % of the plant height. No tillers survived without water for more than 3 weeks. Exposure to salt spray had no effect on shoot survival. Immersion in seawater significantly reduced survival—exposure to seawater, equivalent to only one high tide immersion event, was sufficient to reduce plant survival in the glasshouse. Burial, desiccation and salt-spray may, on occasion, be responsible for either preventing the regeneration of A. arenaria rhizomes or limiting the survival of the resultant plants, but exposure to wave activity determines the viability of a population.

Inferences from the human skeletal material of the Early Iron Age cemetery at Agios Dimitrios, Fthiotis, Central Greece

The Geometric cemetery of Agios Dimitrios (850–740 B.C.) yielded a human osteological sample, with an MNI of 51 and equal numbers of males and females and adults and subadults. This site is of significant archaeological importance, as it provides information on human health status, diet, and activity patterns as well as mortuary behavior for a little studied time period. The results, including a) stable carbon and nitrogen isotopic data suggesting a C3 low-protein plant diet, b) relatively high infant mortality, c) low stature estimates, d) significant prevalence of possible anemic conditions, and e) high dental infection and loss rates, all point to a rapidly increasing, stressed, and relatively malnourished population which did not exploit nearby marine resources, experienced suboptimal living conditions, and could not reach its biological potential. Furthermore, the study of this group provides evidence of equal burial treatment of all age and sex categories, no dietary differences in terms of sex and status, and no sex differentiation in pathological conditions.